Gas turbine airfoils exposed to hot combustion gases have been cooled by forming passageways within the airfoil and passing a cooling fluid through the passageways to connectively cool the airfoil. Such cooled airfoils may include a serpentine, multiple-pass flow path to provide sufficient convective cooling to maintain all portions of the airfoil at a relatively uniform temperature. In addition, the cooling fluid flow may be allowed to exit an interior of the airfoil at desired locations to provide film cooling of an external surface of the airfoil. One of the problems facing designers of airfoils exposed to hot combustion gases is that the airfoils need to be sufficiently strong to withstand forces applied to it during operation of the gas turbine, yet still retain an ability to be cooled effectively to prevent thermal fatigue. Reducing an amount of material used to form the airfoil, such as by making airfoil walls thinner, may reduce an amount of a cooling fluid flow required, but using less material to form the airfoil may adversely reduce a strength of the airfoil. Conversely, increasing an amount of material used to form the airfoil may make the airfoil stronger, but reduce the ability of the airfoil to be cooled sufficiently to prevent thermal fatigue. Furthermore, it is generally desired to keep the trailing edge of the airfoil relatively thin to achieve a desired aerodynamic efficiency. However, a thin trailing edge may increase the likelihood of failure of the trailing edge, for example, under the high centrifugal stresses imposed on it during turbine operation.